Thrombosis, the formation or presence of a blood clot inside a blood vessel or cavity of the heart, is a common but elusive illness that can result in suffering and death if not recognized and treated effectively. Thrombosis occurs in many individuals each year. Death can occur when thrombi break off and form pulmonary emboli, which pass to and obstruct the arteries of the lungs. Thrombosis and pulmonary embolism (PE) most often complicate the course of sick, hospitalized patients but may also affect ambulatory and otherwise healthy persons. It is estimated that each year numerous patients develop PE and that thousands die of this complication. PE is now the most frequent cause of death associated with childbirth.
A number of devices for use in a thrombectomy, a procedure to remove thrombus, have been proposed. Existing technology for the removal of thrombus formation may generally be categorized as suitable for removing either wall adherent thrombus or non-wall adherent thrombus. Devices for removing wall adherent thrombus effectively cut such thrombus into small fragments but do not remove it. Devices for removing non-wall adherent thrombus macerate and aspirate thrombus, but do not effectively remove wall adherent thrombus.
In addition to thrombosis, another major medical problem in the United States is heart disease produced by atherosclerosis. In atherosclerosis, plaque forms in an artery and can completely occlude the artery. If complete blockage occurs, stasis of blood can lead to thrombus formation along the arterial wall. The use of a balloon to open a closed body cavity has been used in the medical profession. The balloon is inserted during a percutaneous procedure. A potential advantage of balloon occlusion is that body cavity obstruction can be temporary; once the threat of embolization has subsided, the balloon can be deflated and removed.
Coronary angioplasty is accomplished using a balloon-tipped catheter inserted through an artery, typically in the groin or arm, to enlarge a narrowing in a coronary artery. Coronary artery disease occurs when cholesterol plaque builds up (as a result of atherosclerosis) in the walls of the arteries to the heart. Angioplasty is successful in opening coronary arteries in about 90% of patients but about 40% of patients with successful coronary angioplasty will develop recurrent narrowing at the site of balloon inflation (i.e., restenosis).
Other conditions face the medical industry in which it would be desirable to remove an obstruction, either adhered to a lumen wall or not, from the inside of the lumen. Such obstructions may be growths or deposits of tissue or cellular structures, such as gall stones and kidney stones. Obstructions may be found in the ducts and passages of the biliary, gastrointestinal, and urological systems, in addition to those found in the vasculature as mentioned above. In many cases, it would be desirable to utilize a device which is capable of simultaneously cutting the obstruction, macerating the obstruction, and aspirating the effluent caused by the cutting and maceration.
Each year, many people are diagnosed as having atherosclerotic heart disease and the other conditions mentioned above. In a population where life expectancy continues to increase, with a corresponding increase in atherosclerotic heart disease and ensuing thrombolytic conditions as well as the other conditions mentioned above, there is an urgent need for an inexpensive, efficient, safe and effective means for removing all types of obstructions, including wall adherent thrombus.